This invention relates to digital communication ports.
It is known to provide a microprocessor system with the capability of communicating with external microprocessor systems utilizing one of the standard serial communication protocols, for example, a RS232 Communication Protocol. To facilitate this communication, it is known to provide a microprocessor system with a communication port. It is customary where the communication is expected to be carried out utilizing a standard communication protocol, for example, an RS232 Communication Protocol, to provide a 9-pin communication port which is specified under the RS232 protocol specification. It is also known to provide a microprocessor control system with a plurality of communication ports where it is desired to accommodate different communication protocols, for example, RS232, RS242, etc.
It is also known, that where different communication protocol specifications permit pin connector compatibility, the microcontroller can be programmed to be able to format digital messages in either protocol. System of the type here referred to, in this context, are characterized in that each unit has its own power supply and each unit is committed to serial communication via a dedicated serial communication port.